A system and method for testing the efficiency of an aeolian monitoring device

Abstract

The application discloses a kind of wind erosion monitoring equipment efficiency test system and method, the system includes wind tunnel laboratory, sand bed, three-dimensional laser scanner, wind erosion monitoring equipment and data processing module, sand bed, three-dimensional laser scanner and wind erosion monitoring equipment are evenly arranged in wind tunnel laboratory, and the surface morphology of entire sand bed before and after blowing erosion is scanned by three-dimensional scanner.The application integrates wind tunnel, standard sand bed and three-dimensional laser scanner, and the efficiency standard test process, test method and data processing process and method of wind erosion monitoring equipment are clarified, with the characteristics of high precision, reproducible and generalizable, which helps to improve the quality of wind erosion monitoring data and lays the foundation for the standardization of soil and water conservation monitoring equipment metrology.

Description

Technical Field

[0001] This invention relates to the field of soil wind erosion monitoring technology, specifically to a wind erosion monitoring equipment efficiency testing system and method. Background Technology

[0002] Soil wind erosion is the process by which fine particles and nutrients in the soil surface are eroded, transported, and deposited under the action of wind. It leads to soil desertification, coarsening, decreased fertility, and structural deterioration in wind-eroded areas, and is one of the main causes of soil degradation in arid, semi-arid, and other arid regions. Conducting soil wind erosion monitoring is an important part of soil and water conservation.

[0003] As an important instrument for observing soil wind erosion processes, the most important characteristic of a sand collector is its sand collection efficiency. The sand collection efficiency of a sand collector is related to its design, wind speed, the size of the moving sand particles, and the collection time. The only way to determine the sand collection efficiency of a sand collector is to compare the sand transport rate observed by the sand collector with that of a standard sand collector under the same location and conditions. However, it is difficult to meet exactly the same experimental conditions in the field, and there is currently no standard sand collector setup. A feasible method is to conduct experiments in a large wind tunnel laboratory under the same testing environment. However, there is currently no unified, replicable, and scalable testing method in large wind tunnel laboratories. This leads to unclear efficiency of the soil wind erosion monitoring instruments currently in use, and the data collected by different instruments cannot achieve uniformity, accuracy, and reliability in measurement values. Summary of the Invention

[0004] This invention provides a wind erosion monitoring equipment efficiency testing system and method to solve the problem that the efficiency levels of existing wind erosion monitoring instruments and equipment are uneven, and there is a lack of unified verification methods and procedures, which leads to inconsistent wind erosion monitoring data values ​​at present, seriously affecting the accuracy and reliability of wind erosion monitoring data.

[0005] According to the first aspect, one embodiment provides a wind erosion monitoring equipment efficiency testing system, the system including a wind tunnel test chamber, a sand bed, a three-dimensional laser scanner, a wind erosion monitoring equipment and a data processing module, wherein the sand bed, the three-dimensional laser scanner and the wind erosion monitoring equipment are all arranged in the wind tunnel test chamber;

[0006] The sand bed is laid horizontally at the bottom of the wind tunnel test chamber and eroded under preset wind speed conditions. The sand material in the sand bed should be replenished in time after each test and stirred to keep the particle size parameters of the sand material in the sand bed as consistent as possible (ideally, completely consistent). Then the surface is smoothed for the next test.

[0007] The three-dimensional laser scanner can be movably positioned above the sand bed and can scan the surface morphology of the entire sand bed before and after erosion. The placement of the three-dimensional scanner is as follows: if the sand collector does not interfere, the three-dimensional scanner is placed in the middle; if the sand collector obstructs the scanning path, the three-dimensional scanner is placed at 1 / 4 of the horizontal distance of the wind tunnel to ensure that half of the sand bed can be completely scanned.

[0008] The wind erosion monitoring equipment includes a sand collector, which is placed at the tail end of the sand bed. The sand collector includes multiple sand collection ports at different heights, and collects sand material through the sand collection ports during the sand bed erosion process.

[0009] The data processing module is used to process the scanning data of the 3D scanner and calculate the unit width sand transport rate based on the 3D scanner observation. It weighs the sand collected by the sand collection port at different heights of the sand collector and calculates the unit width sand transport rate based on the wind erosion monitoring equipment observation. The unit width sand transport rate based on the 3D scanner observation is used as the absolute sand transport rate. The efficiency of the wind erosion monitoring equipment is obtained by dividing the unit width sand transport rate based on the wind erosion monitoring equipment observation by the unit width sand transport rate based on the 3D scanner observation.

[0010] Furthermore, the gaps between the two sides of the sand bed and the sidewalls of the wind tunnel are filled with gypsum board or other boards until flush; a gentle slope of a predetermined length is provided on the windward side as a transition between the bottom plate of the wind tunnel test chamber and the sand bed; and a pre-determined thickness of MDF board is used to seal the tail of the sand bed; the purpose is to ensure that the influence of the surrounding environment of the sand bed on the airflow is minimized.

[0011] Furthermore, reflective strips are affixed to the sand bed boundary to facilitate the determination of the sand bed boundary by a 3D laser scanner.

[0012] Furthermore, the wind tunnel test chamber is equipped with an anemometer to record wind speed conditions during the test.

[0013] Furthermore, the scanning data from the 3D scanner is processed and the unit width sediment transport rate based on the 3D scanner observations is calculated, specifically including:

[0014] The point cloud data obtained by the 3D scanner is subjected to noise reduction processing;

[0015] The denoised point cloud data is vectorized to generate vector data;

[0016] Based on the obtained vector data, the sand bed boundary is visually identified in CAD software, and the sand bed boundary vector is drawn using the line offset tool.

[0017] Using ArcGIS software's 3D analysis tools, point cloud data is imported to generate an irregular triangular network, followed by the generation of a digital elevation model, which is then exported as raster data.

[0018] Based on the obtained raster data, the effective test sand bed segment raster data is extracted using the drawn sand bed boundary vector mask;

[0019] The raster surface analysis was performed using the cut and fill calculation tool in ArcGIS software to obtain the erosion volume of the sand bed surface before and after erosion. Combined with the sand bed bulk density, the wind erosion was calculated, and the wind erosion was divided by the sand bed width to obtain the unit width sand transport rate.

[0020] Furthermore, the sand collected from the sand collection ports at different heights of the sand collector was weighed, and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated, specifically including:

[0021] The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights.

[0022] The variation of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area of ​​the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate observed by wind erosion monitoring equipment.

[0023] Furthermore, the erosion of the sand bed under preset wind speed conditions specifically includes:

[0024] The wind speed was set in the range of 6-14 m / s, with a wind speed gradient of 2 m / s. The observed wind speeds were 6 m / s, 8 m / s, 10 m / s, 12 m / s, and 14 m / s.

[0025] According to a second aspect, one embodiment provides a testing method for a wind erosion monitoring equipment efficiency testing system, the method comprising:

[0026] A sand bed, a 3D laser scanner, and a sand collector were set up in the wind tunnel test chamber.

[0027] The surface morphology of the sand bed before erosion was scanned using a 3D laser scanner;

[0028] Start the blower and erode the sand bed under the preset wind speed conditions;

[0029] During the sand bed erosion process, the sand collector collects sand material through sand collection ports at different heights;

[0030] The surface morphology of the sand bed after erosion was scanned using a 3D laser scanner;

[0031] The sand collected by the sand collection port at different heights of the sand collector is bagged and recycled;

[0032] The scanning data from the 3D scanner is processed and the unit width sand transport rate based on the observations of the 3D scanner is calculated.

[0033] The sand collected by the sand collection port at different heights of the sand collector was weighed and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated.

[0034] The efficiency of the wind erosion monitoring equipment is obtained by dividing the unit width sand transport rate observed by the three-dimensional scanner by the unit width sand transport rate observed by the three-dimensional scanner.

[0035] Furthermore, the scanning data from the 3D scanner is processed and the unit width sediment transport rate based on the 3D scanner observations is calculated, specifically including:

[0036] The point cloud data obtained by the 3D scanner is subjected to noise reduction processing;

[0037] The denoised point cloud data is vectorized to generate vector data;

[0038] Based on the obtained vector data, the sand bed boundary is visually identified in CAD software, and the sand bed boundary vector is drawn using the line offset tool.

[0039] Using ArcGIS software's 3D analysis tools, point cloud data is imported, an irregular triangular network is generated, a DEM is then generated, and the data is exported as raster data.

[0040] Based on the obtained raster data, the effective test sand bed segment raster data is extracted using the drawn sand bed boundary vector mask;

[0041] The raster surface analysis was performed using the cut and fill calculation tool in ArcGIS software to obtain the erosion volume of the sand bed surface before and after erosion. Combined with the sand bed bulk density, the wind erosion was calculated, and the wind erosion was divided by the sand bed width to obtain the unit width sand transport rate.

[0042] Furthermore, the sand collected from the sand collection ports at different heights of the sand collector was weighed, and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated, specifically including:

[0043] The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights.

[0044] The variation of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area of ​​the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate observed by wind erosion monitoring equipment.

[0045] Compared with the prior art, the wind erosion monitoring equipment efficiency testing system and method provided by the present invention have the following beneficial effects:

[0046] (1) This invention clarifies the test process, test method and data processing process and method for the efficiency standard of wind erosion monitoring equipment. It has the characteristics of high accuracy, reproducibility and scalability, which effectively promotes the development of the metrology work of wind erosion monitoring equipment, helps to improve the quality of wind erosion monitoring data, and lays the foundation for the metrology standardization of soil and water conservation monitoring equipment.

[0047] (2) This invention can detect the collection efficiency of various types of wind erosion monitoring equipment used in wind erosion monitoring at present, calibrate the efficiency parameters of each sand collector, and thus unify the data collected by different types of wind erosion monitoring equipment and unify the measurement values ​​of different wind erosion monitoring equipment.

[0048] (3) The present invention uses a high-precision three-dimensional scanner, which can improve the monitoring accuracy of micro-topographic changes to 5mm. Based on the accurate surface morphology change data, the volume of sand loss per unit time can be obtained, and then the bulk density can be converted to the mass loss of sand per unit time. The sand transport rate per unit width per unit time can be calculated and used as the absolute sand transport rate. Its value is close to the true value, and the test process is clear and repeatable. It has the advantages of high test accuracy and repeatability. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of a sand collector test for a wind erosion monitoring equipment efficiency testing system according to an embodiment of the present invention;

[0050] Figure 2 A wind tunnel layout plan of an efficiency testing system for wind erosion monitoring equipment provided in one embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of a sand box verification test for an efficiency testing system of a wind erosion monitoring device provided in one embodiment of the present invention;

[0052] Figure 4 This is a three-dimensional view of a sandbox verification test of a wind erosion monitoring equipment efficiency testing system provided in one embodiment of the present invention.

[0053] In the diagram: 1-Wind tunnel laboratory; 2-Sand bed; 3-3D laser scanner; 4-Sand collector; 5-Sand collection box. Detailed Implementation

[0054] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. In the following embodiments, many details are described to facilitate a better understanding of the invention. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present invention are not shown or described in the specification. This is to avoid obscuring the core parts of the invention with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0055] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0056] The first embodiment of the present invention provides a wind erosion monitoring equipment efficiency testing system, which includes a wind tunnel test chamber 1, a sand bed 2, a three-dimensional laser scanner 3, wind erosion monitoring equipment, and a data processing module.

[0057] In this embodiment, the wind erosion monitoring equipment uses a sand collector 4. The sand bed 2, the 3D laser scanner 3, and the sand collector 4 are all installed inside the wind tunnel test chamber 1. Figure 1 As shown, Figure 1 The direction of the middle arrow indicates the wind direction.

[0058] In this embodiment, the plan view of the wind tunnel test chamber 1 is as follows: Figure 2 As shown, it mainly includes the gas gathering section, power section, large opening angle section, stabilization section, contraction section, test section, and diffusion section.

[0059] The sand bed 2 is laid horizontally at the bottom of the wind tunnel test chamber 1 and eroded under preset wind speed conditions; the three-dimensional laser scanner 3 is movably set above the sand bed 2 to ensure that the entire area of ​​the sand bed 2 can be scanned and the surface morphology of the sand bed 2 before erosion is scanned; the sand collector 4 is placed at the tail end of the sand bed 2 and includes multiple sand collection ports at different heights. During the erosion of the sand bed 2, sand material is collected through the sand collection ports.

[0060] In this embodiment, the gaps between the two sides of the sand bed 2 and the sidewalls of the wind tunnel chamber 1 are filled with gypsum board until flush; a 50cm long gentle slope is set on the windward side as a transition between the bottom plate of the wind tunnel chamber 1 and the sand bed 2; the tail of the sand bed 2 is sealed with 1.8cm thick OSB board; the purpose of these settings is to minimize the impact of the surrounding environment on the airflow. Reflective strips are affixed to the boundary of the sand bed 2 so that the three-dimensional laser scanner 3 can determine the boundary of the sand bed 2.

[0061] In this embodiment, a wind speed profiler is also installed in the wind tunnel test chamber 1 to record the wind speed conditions during the test.

[0062] Wind speed measurement range determination: According to the meteorological data from the field survey of the wind erosion monitoring station, except in extreme weather, the wind speed range is below 18 m / s. According to the wind tunnel pre-test results, when the wind speed reaches 16 m / s, the sand flow exhibits a floating phenomenon, which leads to deviation in the verification results. Therefore, in this embodiment, the wind speed is set in the range of 6-14 m / s, with a wind speed gradient of 2 m / s. The observed wind speeds are 6 m / s, 8 m / s, 10 m / s, 12 m / s, and 14 m / s.

[0063] The parameters for sand bed 2 are set as follows: Under a wind speed of 10 m / s, the length and width are greater than 1 m, and the thickness should be greater than the erosion time multiplied by the wind erosion rate of 0.31 cm / min; under a wind speed of 12 m / s, the length is greater than 1.25 m and the width is greater than 1 m, and the thickness should be greater than the erosion time multiplied by the wind erosion rate of 0.42 cm / min; under a wind speed of 14 m / s, the length is greater than 1.5 m and the width is greater than 1 m, and the thickness should be greater than the erosion time multiplied by the wind erosion rate of 0.93 cm / min. Considering the stability of the experiment, the thickness of sand bed 2 can be appropriately increased by 2 cm. The particle size parameters of the sand material in sand bed 2 are shown in Table 1.

[0064] Table 1. Sand particle size parameters of sand bed

[0065]

[0066] Erosion time: Generally, the erosion time is 10 minutes, and 5 minutes under a wind speed of 14 m / s.

[0067] In this embodiment, the sand collector 4 is positioned horizontally in the center of the sand bed 2. To avoid turbulence, the downwind side is filled with plasterboard, with a filling width of 1 meter. Since the 3D laser scanner 3, when positioned in the center, obstructs the view of the sand bed during terrain scanning, resulting in incomplete data, the scanner can be positioned at the horizontal 1 / 4 position to ensure that half of the sand bed can be completely scanned. Based on the above experimental results, an edge effect exists on both sides of the sand bed within 20cm, and the 130cm width of the sand bed in the center is within the effective experimental range. Therefore, it is feasible to calibrate the efficiency of the sand collector using data within a certain width range of the effective sand bed.

[0068] The sand collector 4 is the wind erosion monitoring equipment to be tested. Models include, for example, a 20-layer sand collector and a 50-layer 1-meter-high continuous sand collector. The sand inlet height of the 20-layer sand collector is 5cm, 10cm, ..., 100cm. The 50-layer 1-meter-high continuous sand collector has a total of 50 sand collection ports, each with an inlet size of 2cm×2cm, and a total height of 1 meter for 50 layers.

[0069] The data processing module is used to process the scanning data of the 3D scanner 3 and calculate the unit width sand transport rate based on the observation of the 3D scanner. It recovers and weighs the sand collected by the sand collection port of the sand collector 4 at different heights and calculates the unit width sand transport rate based on the observation of the wind erosion monitoring equipment. The unit width sand transport rate based on the observation of the 3D scanner is used as the absolute sand transport rate. The efficiency of the wind erosion monitoring equipment is obtained by dividing the unit width sand transport rate based on the observation of the wind erosion monitoring equipment by the unit width sand transport rate based on the observation of the 3D scanner.

[0070] The specific steps for calculating the unit width sediment transport rate based on 3D scanner observations are as follows:

[0071] 1) Perform noise reduction processing on the point cloud data obtained from the 3D scanner.

[0072] Specifically, since only one scanning station is used for each scan in the experiment, the issue of point cloud data stitching is not involved. First, the scanned point cloud data is imported into RISCAN PRO software for noise reduction. The purpose of noise reduction is to avoid redundant noise data from affecting the data involved in the experiment. Noise reduction is carried out by manually deleting point cloud data by visual inspection using software tools.

[0073] 2) Vectorize the denoised point cloud data to generate vector data.

[0074] Specifically, the point cloud data of the experimental area after noise reduction is vectorized, and the generated vector data is saved to the structure directory of the corresponding site.

[0075] 3) Based on the obtained vector data, visually identify the sand bed boundary in CAD software, and draw the sand bed boundary vector using the line offset tool.

[0076] 4) Using ArcGIS software's 3D analysis tool ("3D analysis" function module), import point cloud data, generate an irregular triangular network, then generate a digital elevation model, and export it as raster data.

[0077] Specifically, first, an irregular triangular network is generated using the tool to create an irregular triangular network. Then, an irregular triangular network to raster data tool is used to generate a digital elevation model (DEM) and export it as raster data.

[0078] 5) Based on the obtained raster data, extract the effective test sand bed segment raster data using the drawn sand bed boundary vector mask.

[0079] 6) Use the cut and fill calculation tool in ArcGIS software to perform raster surface analysis, obtain the erosion volume of the sand bed surface before and after erosion, combine it with the sand bed bulk density, calculate the wind erosion, and divide the wind erosion by the sand bed width to obtain the unit width sand transport rate.

[0080] The specific steps for calculating the unit width sand transport rate based on wind erosion monitoring equipment are as follows:

[0081] 1) The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights.

[0082] 2) The variation law of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area value of the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate based on wind erosion monitoring equipment.

[0083] Specifically, taking Origin plotting software as an example, with height x and corresponding height-based sand transport rate y, a scatter plot is generated, a fitting model is fitted, a fitting curve is selected, and the quick analysis (S) - integration (I) function is used to set the initial value of height (x) to 0~100cm, select to limit the interpolation curve to "interpolate to rectangle edge", the area type is "mathematical area", and the area value of the fitted curve from 0 to 100cm is calculated by integration, which is the single-width sand transport rate obtained from the data collected by the sand collector 4.

[0084] Taking the exploration of the optimal sand transport model for a 20-layer sand collector under ideal conditions as an example, three two-parameter models—exponential function, power function, and logarithmic function—were used to fit the sand transport data of the 20-layer sand collector under different wind speed conditions. The fitted functions and R... 2 The coefficient of determination (COP) and p-value (significance index) are shown in Table 2. When the wind speed is 10-14 m / s, the p-values ​​of all three functions are below 0.05, indicating a good fit correlation. 2Among them, the power function and the exponential function show better fitting results (R²). 2 >0.990), worst logarithmic function (R 2 <0.5). Therefore, both exponential and power functions can effectively simulate the variation of sediment transport rate with height within the 0-100cm height range under ideal conditions.

[0085] Table 2. Sand transport model of 20-layer sand collector at 10~14 m / s

[0086]

[0087] Where: a and b are constants, x is the height, and y is the sediment transport rate.

[0088] In this embodiment, the feasibility and accuracy of the calculation results from the 3D laser scanner were also verified using a sandbox collection method, as detailed below:

[0089] 1) Specific test setup as follows Figure 3 and Figure 4 As shown, the initial parameters for sand bed 2 are a width of 1.7m, a length of 4m, and a thickness of 8cm. A sand collection box 5 is installed at the tail end of sand bed 2. The sand collection box 5 is a 10×10×8 acrylic pentahedron with an open top, a wall thickness of 3mm, a length of 3.5m (determined based on preliminary test results, where the furthest jump distance of sand particles under maximum wind speed is less than 3.5m), and a width of 1.7m. To prevent the formation of vortices within the sand collection box 5 and secondary erosion of the deposited sand, artificial turf is laid at the bottom of each sand collection box 5 to increase roughness and ensure the accuracy of sand collection.

[0090] 2) Specific experimental steps: 1) Set up sand bed 2, sand collection box and three-dimensional laser scanner 3. Fill the gap between sand bed 2 and the wind tunnel side wall with gypsum board; 2) Use three-dimensional laser scanner 3 to scan the surface morphology of sand bed 2 before erosion; 3) Start the fan and erode for 10 minutes according to the observed wind speed; 4) Use three-dimensional laser scanner 3 to scan the surface morphology of sand bed 2 after erosion, weigh the sand collection box 5 according to the number, and complete one measurement.

[0091] 3) The experimental results verify that the sand transport rate calculated by the three-dimensional laser scanner can be used as the absolute sand transport rate under the experimental conditions.

[0092] This invention uses a three-dimensional laser scanner to accurately observe the volume of erosion changes, and combines this with the bulk density of the test sand material to obtain high-precision net wind erosion data per unit time and unit width. The feasibility and accuracy of the calculation results of the three-dimensional laser scanner are verified by using a sand collection box method. Based on the experimental conditions and process described in this invention, at wind speeds of 10 m / s, 12 m / s, and 14 m / s, the sand collection efficiency of the sand collection box is 64.23% to 86.18% as measured by the laser scanner, and the sand collection efficiency increases with increasing wind speed.

[0093] Based on the wind erosion monitoring equipment efficiency testing system disclosed above, this invention also discloses a testing method for the wind erosion monitoring equipment efficiency testing system, the method specifically including:

[0094] S100, a sand bed, a three-dimensional laser scanner and a sand collector are set up in the wind tunnel test chamber;

[0095] S200 uses a 3D laser scanner to scan the surface morphology of the sand bed before erosion;

[0096] S300, start the fan and erode the sand bed under the preset wind speed conditions;

[0097] S400, during the sand bed erosion process, the sand collector collects sand material through sand collection ports at different heights;

[0098] S500 uses a 3D laser scanner to scan the surface morphology of the sand bed after erosion;

[0099] S600 collects sand from sand collection ports at different heights of the sand collector and then bags it for recycling.

[0100] S700 processes the scanning data from the 3D scanner and calculates the unit width sand transport rate based on the observations of the 3D scanner.

[0101] S800 weighs the sand collected by the sand collection port at different heights of the sand collector and calculates the unit width sand transport rate based on the observation of the wind erosion monitoring equipment.

[0102] S900 uses the unit width sand transport rate observed based on a 3D scanner as the absolute sand transport rate, and divides the unit width sand transport rate observed based on the wind erosion monitoring equipment by the unit width sand transport rate observed based on the 3D scanner to obtain the efficiency of the wind erosion monitoring equipment.

[0103] Furthermore, the scanning data from the 3D scanner is processed and the unit width sediment transport rate based on the 3D scanner observations is calculated, specifically including:

[0104] The point cloud data obtained by the 3D scanner is subjected to noise reduction processing;

[0105] The denoised point cloud data is vectorized to generate vector data;

[0106] Based on the obtained vector data, the sand bed boundary is visually identified in CAD software, and the sand bed boundary vector is drawn using the line offset tool.

[0107] Using ArcGIS software's 3D analysis tools, point cloud data is imported, an irregular triangular network is generated, a DEM is then generated, and the data is exported as raster data.

[0108] Based on the obtained raster data, the effective test sand bed segment raster data is extracted using the drawn sand bed boundary vector mask;

[0109] The raster surface analysis was performed using the cut and fill calculation tool in ArcGIS software to obtain the erosion volume of the sand bed surface before and after erosion. Combined with the sand bed bulk density, the wind erosion was calculated, and the wind erosion was divided by the sand bed width to obtain the unit width sand transport rate.

[0110] Furthermore, the sand collected from the sand collection ports at different heights of the sand collector was weighed, and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated, specifically including:

[0111] The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights.

[0112] The variation of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area of ​​the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate observed by wind erosion monitoring equipment.

[0113] It should be noted that for a detailed description of the testing method of the wind erosion monitoring equipment efficiency testing system provided in the embodiments of the present invention, please refer to the relevant description of the wind erosion monitoring equipment efficiency testing system provided in the embodiments of the present invention, which will not be repeated here.

[0114] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A wind erosion monitoring equipment efficiency testing system, characterized in that, The system includes a wind tunnel test chamber, a sand bed, a three-dimensional laser scanner, wind erosion monitoring equipment, and a data processing module. The sand bed, the three-dimensional laser scanner, and the wind erosion monitoring equipment are all installed in the wind tunnel test chamber. The sand bed is laid horizontally at the bottom of the wind tunnel test chamber and eroded under preset wind speed conditions; The three-dimensional laser scanner can be movably positioned above the sand bed and can scan the surface morphology of the entire sand bed before and after erosion. The wind erosion monitoring equipment includes a sand collector, which is placed at the tail end of the sand bed. The sand collector includes multiple sand collection ports at different heights, and collects sand material through the sand collection ports during the sand bed erosion process. The data processing module is used to process the scanning data of the 3D scanner and calculate the unit width sand transport rate based on the 3D scanner observation. It weighs the sand collected by the sand collection port at different heights of the sand collector and calculates the unit width sand transport rate based on the wind erosion monitoring equipment observation. The unit width sand transport rate based on the 3D scanner observation is used as the absolute sand transport rate. The efficiency of the wind erosion monitoring equipment is obtained by dividing the unit width sand transport rate based on the wind erosion monitoring equipment observation by the unit width sand transport rate based on the 3D scanner observation. The gaps between the two sides of the sand bed and the sidewalls of the wind tunnel test chamber are filled with gypsum board until flush; a gentle slope of a predetermined length is set on the windward side as a transition between the bottom plate of the wind tunnel test chamber and the sand bed; and the tail of the sand bed is sealed with OSB board of a predetermined thickness. Reflective strips are affixed to the boundaries of the sand bed to facilitate the determination of the sand bed boundaries by a 3D laser scanner; The scanning data from the 3D scanner is processed and the unit width sediment transport rate based on the 3D scanner observations is calculated, specifically including: The point cloud data obtained by the 3D scanner is subjected to noise reduction processing; The denoised point cloud data is vectorized to generate vector data; Based on the obtained vector data, the sand bed boundary is visually identified in CAD software, and the sand bed boundary vector is drawn using the line offset tool. Using ArcGIS software's 3D analysis tools, point cloud data is imported to generate an irregular triangular network, followed by the generation of a digital elevation model, which is then exported as raster data. Based on the obtained raster data, the effective test sand bed segment raster data is extracted using the drawn sand bed boundary vector mask; The raster surface analysis was performed using the cut and fill calculation tool in ArcGIS software to obtain the erosion volume of the sand bed surface before and after erosion. Combined with the sand bed bulk density, the wind erosion was calculated. The wind erosion was divided by the sand bed width to obtain the sand transport rate per unit width. The sand collected from the sand collection ports at different heights of the sand collector was weighed, and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated. Specifically, this included: The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights. The variation of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area of ​​the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate observed by wind erosion monitoring equipment.

2. The wind erosion monitoring equipment efficiency testing system as described in claim 1, characterized in that, The wind tunnel test chamber is equipped with an anemometer to record wind speed conditions during testing.

3. The wind erosion monitoring equipment efficiency testing system as described in claim 1, characterized in that, Erosion of the sand bed under preset wind speed conditions specifically includes: The wind speed was set in the range of 6-14 m / s, with a wind speed gradient of 2 m / s. The observed wind speeds were 6 m / s, 8 m / s, 10 m / s, 12 m / s, and 14 m / s.

4. The test method for a wind erosion monitoring equipment efficiency testing system as described in any one of claims 1-3, characterized in that, The method includes: A sand bed, a 3D laser scanner, and a sand collector were set up in the wind tunnel test chamber. The surface morphology of the sand bed before erosion was scanned using a 3D laser scanner; Start the blower and erode the sand bed under the preset wind speed conditions; During the sand bed erosion process, the sand collector collects sand material through sand collection ports at different heights; The surface morphology of the sand bed after erosion was scanned using a 3D laser scanner; The sand collected by the sand collection port at different heights of the sand collector is bagged and recycled; The scanning data from the 3D scanner is processed and the unit width sand transport rate based on the observations of the 3D scanner is calculated. The sand collected by the sand collection port at different heights of the sand collector was weighed and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated. The efficiency of the wind erosion monitoring equipment is obtained by dividing the unit width sand transport rate observed by the three-dimensional scanner by the unit width sand transport rate observed by the three-dimensional scanner.

5. The test method for a wind erosion monitoring equipment efficiency testing system as described in claim 4, characterized in that, The scanning data from the 3D scanner is processed and the unit width sediment transport rate based on the 3D scanner observations is calculated, specifically including: The point cloud data obtained by the 3D scanner is subjected to noise reduction processing; The denoised point cloud data is vectorized to generate vector data; Based on the obtained vector data, the sand bed boundary is visually identified in CAD software, and the sand bed boundary vector is drawn using the line offset tool. Using ArcGIS software's 3D analysis tools, point cloud data is imported, an irregular triangular network is generated, a DEM is then generated, and the data is exported as raster data. Based on the obtained raster data, the effective test sand bed segment raster data is extracted using the drawn sand bed boundary vector mask; The raster surface analysis was performed using the cut and fill calculation tool in ArcGIS software to obtain the erosion volume of the sand bed surface before and after erosion. Combined with the sand bed bulk density, the wind erosion was calculated, and the wind erosion was divided by the sand bed width to obtain the unit width sand transport rate.

6. The testing method for the efficiency testing system of wind erosion monitoring equipment as described in claim 4, characterized in that, The sand collected from the sand collection ports at different heights of the sand collector was weighed, and the unit width sand transport rate observed by the wind erosion monitoring equipment was calculated. Specifically, this included: The mass of sand collected at different heights within a preset erosion time is obtained by weighing, and then divided by the erosion time and the sand collection inlet area to obtain the sand transport rate of different heights. The variation of sand transport rate with height under preset wind speed conditions is plotted using mathematical statistics software. A suitable fitting model is selected based on the distribution characteristics of the scatter points, and a fitting curve is generated. The area of ​​the fitting curve within the preset height range is calculated by integration, thus obtaining the unit width sand transport rate observed by wind erosion monitoring equipment.

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